core/crypto: Expose the block sizes for every hash algorithm

While I just went and made this private, this information is required
for keying HMAC.

core/crypto/legacy/keccak/keccak.odin

@@ -27,6 +27,15 @@ DIGEST_SIZE_384 :: 48
 // DIGEST_SIZE_512 is the Keccak-512 digest size.
 DIGEST_SIZE_512 :: 64
 
+// BLOCK_SIZE_224 is the Keccak-224 block size in bytes.
+BLOCK_SIZE_224 :: _sha3.RATE_224
+// BLOCK_SIZE_256 is the Keccak-256 block size in bytes.
+BLOCK_SIZE_256 :: _sha3.RATE_256
+// BLOCK_SIZE_384 is the Keccak-384 block size in bytes.
+BLOCK_SIZE_384 :: _sha3.RATE_384
+// BLOCK_SIZE_512 is the Keccak-512 block size in bytes.
+BLOCK_SIZE_512 :: _sha3.RATE_512
+
 // Context is a Keccak instance.
 Context :: distinct _sha3.Context
 

core/crypto/legacy/md5/md5.odin

@@ -22,9 +22,12 @@ import "core:encoding/endian"
 import "core:math/bits"
 import "core:mem"
 
-// DIGEST_SIZE is the MD5 digest size.
+// DIGEST_SIZE is the MD5 digest size in bytes.
 DIGEST_SIZE :: 16
 
+// BLOCK_SIZE is the MD5 block size in bytes.
+BLOCK_SIZE :: 64
+
 // Context is a MD5 instance.
 Context :: struct {
 	data:    [BLOCK_SIZE]byte,
@@ -131,9 +134,6 @@ reset :: proc(ctx: ^$T) {
     MD5 implementation
 */
 
-@(private)
-BLOCK_SIZE :: 64
-
 /*
     @note(zh): F, G, H and I, as mentioned in the RFC, have been inlined into FF, GG, HH
     and II respectively, instead of declaring them separately.

core/crypto/legacy/sha1/sha1.odin

@@ -23,9 +23,12 @@ import "core:encoding/endian"
 import "core:math/bits"
 import "core:mem"
 
-// DIGEST_SIZE is the SHA1 digest size.
+// DIGEST_SIZE is the SHA1 digest size in bytes.
 DIGEST_SIZE :: 20
 
+// BLOCK_SIZE is the SHA1 block size in bytes.
+BLOCK_SIZE :: 64
+
 // Context is a SHA1 instance.
 Context :: struct {
 	data:    [BLOCK_SIZE]byte,
@@ -138,9 +141,6 @@ reset :: proc(ctx: ^$T) {
     SHA1 implementation
 */
 
-@(private)
-BLOCK_SIZE :: 64
-
 @(private)
 transform :: proc "contextless" (ctx: ^Context, data: []byte) {
 	a, b, c, d, e, i, t: u32